Olex File with 2000- 3000 waypoints and routes
How do I change waypoints from Olex plotter to be compatible with Open CPN
OpenCPN uses the GPX format to store waypoints. If Olex can export this format, Yes.
There are lots of free tools that convert various formats to/from GPX.
How to convert to GPX for use in OpenCPN?
NewGPSU Olex File Converter Utility New
Version 1.05, Released 2-JAN-2013
A program for converting OLEX files to/from GPS Utility Format Files.
GPS Utility - Download Not Free Registered version does unlimited number of waypoints.
Does Open CPN support NMEA 0183 sentence called TLL (Target Latitude, Longitude).
Yes, OpenCPN supports both TLL and TTM messages, see Radar Targets
(not very well tested yet).
Another alternative: GPSBabel: convert, upload, download data from GPS and Map programs